Hole fill composition and method for filling holes in a substrate

ABSTRACT

A composition usable in hole filling of a metal layer and to planarize the metal layer is provided. The metal layer is part of a substrate which can be part of a multilayer printed circuit board or chip carrier. The composition comprises a fluoropolymer dielectric metal, a filler material, and a coupling agent, the filler material having at least a partial coating of the coupling agent.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a division of application Ser. No.09/863,961, filed May 23, 2001, now U.S. Pat. No. ______.

FIELD OF THE INVENTION

[0002] This invention relates to a composition for filling holes in asubstrate wherein the substrate can be part of a multi-layer printedcircuit board or chip carrier. Specifically this invention defines anewand unique hole fill composition and method of filling such holes in asubstrate which provides a substantially planar substrate surface at thefilled hole locations wherein the filled hole substrate can form part ofthe completed multi-layer printed circuit board or chip carrier.

BACKGROUND OF THE INVENTION

[0003] Many known current printed circuit board constructions requireone or more external conductive layers, e.g., circuitry and/or pads formounting components thereon, and, given today's increased functionaldemands, a plurality of internal conductive planes, e.g., signal, powerand/or ground. To provide effective interconnections between suchsurface components and the board's conductive circuitry, internal planesand/or pads, the use of conductive through holes has been adoptedwherein several such holes are formed in the board and electricallycoupled in a selective manner to internal and external conductiveelements. Such holes typically include a conductive, e.g., copper, layeras part thereof which in turn contacts the also typically coppercircuitry, pads and/or internal planes.

[0004] The term “through hole” or simply “hole” as used herein is meantto include both conductive and non-conductive apertures which may extendentirely through the circuit board or even only partly therethrough(such partial holes are often also called “vias” in the circuit boardfield), including between only one or more internal layers without beingexternally exposed. Examples of various circuit board structures whichinclude holes of these types are defined in several published documents,including the following U.S. Letters Patents, issued on the datesidentified: U.S. Pat. No. Inventors Filing Date 4,704,791 Chellis et al.Nov. 10, 1987 4,435,480 Hart et al. Dec. 23, 1993 5,450,290 Boyko et al.Sep. 12, 1995 5,487,218 Bhatt et al. Jan. 30, 1996 5,557,844 Bhatt etal. Sep. 24, 1996 5,571,593 Arldt et al. Nov. 5, 1996 5,662,987 Mizumotoet al. Sep. 2, 1997

[0005] All of these patents are assigned to the same assignee as thepresent invention and are incorporated herein by reference.

[0006] Printed circuit boards of all the above type are particularlyadapted for having one or more (usually several) electrical components,e.g., semiconductor chips, capacitors, resistors, etc., mounted on anexternal surface thereof and coupled to various, selected internalconductive planes within the board's dielectric substrate. As demandsfor increased levels of integration in semiconductor chips and otherelectrical components continue, parallel demands call for concurrentincreased functional capabilities, e.g., increased circuit densities, inprinted circuit boards adapted for use with such components. Suchdemands further emphasize the growing need for more closely spacedelectrical components on the board's outer surfaces. For those boardspossessing greater functional capabilities and therefore which useseveral through holes therein, it is highly desirable to position theelectrical components directly over the holes to maximize board realestate while assuring a compact, miniaturized final board product.

[0007] Increased demands such as those above are particularlysignificant when it is desirable to couple what are referred to as ballgrid array.(BGA) or similar components directly onto the board's outerconductive layer(s). These components typically include a semiconductorchip electrically coupled to a plurality of highly dense conductors,e.g., solder ball elements, closely positioned in a fixed pattern on thecomponent's undersurface. This is also the case for directly mountedsemiconductor chips (also known in this technology as direct chip attach(or DCA components) wherein a dense pattern of several minute solderballs are arranged on the chip's small undersurface (that directlyfacing the underlying circuit board). In this case, the circuit boardmay also be referred to as a chip carrier.

[0008] In many of today's advanced chip carriers, the basic buildingblock of the chip carrier is a metal ground plane that has been etchedto form a personalized ground plane having clearance holes. Thepersonalized ground plane can then be laminated on both sides with afluoropolymer or other dielectric material and a metal foil, preferablycopper foil. The metal foil is then circuitized to form a signalcarrying layer. This circuitized structure may be defined as a signalcore. Subsequent additions of fluoropolymer or other dielectric layersand metal foil layers are “built up” on the signal core and can formpower and additional signals layers which are ultimately built up to amultilayer chip carrier structure. The presence of clearance holes in asignal core may lead to a non-planar signal core outside surface whichcan affect the planarity of subsequent layers “built up” on the signalcore (and ultimately the planarity of the surface of the multilayer chipcarrier on which the semiconductor chip is to be mounted.) This isbelieved to be caused by the limited flow characteristics of thefluoropolymer or other dielectric material during the lamination phaseof signal core manufacture.

[0009] It is believed that a new hole fill composition and a method ofmaking a substrate having at least one hole (and possibly several)therein which is filled with the new hole fill composition willsubstantially prevent non-planarity of the signal core outside surfaceand lead to a substantially planar multilayer printed circuit board orchip carrier surface when the signal core is used in the manufacture ofthe multilayer printed circuit board or chip carrier. This wouldrepresent a significant advancement in the art.

SUMMARY OF THE INVENTION

[0010] Accordingly, it is the object of this invention to provide a newand unique composition which in turn may be used as a hole fill in ametal layer of a substrate.

[0011] Another object of this invention is to provide a method of makingsuch a composition.

[0012] Yet another object of this invention is to provide a substrateincluding a metal layer having at least one through hole therein and amixture of a fluoropolymer dielectric material and a filler materialsubstantially filling the through hole. The mixture will provide asubstantially planar filled hole substrate and will improve theplanarity of the multilayer printed circuit board or chip carrier ofwhich the substrate is a part.

[0013] Still yet another object of the invention is to provide a methodof making such a substrate.

[0014] The invention is adaptable to mass production and reduces thedefect level and lowers the cost of product made with this invention.

[0015] According to one aspect of the invention, there is provided a thefill composition comprising a fluoropolymer dielectric material, afiller material, and a coupling agent, the filler material having atleast a partial coating of the coupling agent thereon.

[0016] According to another aspect of the invention, there is provided ahole fill composition comprising a fluoropolymer dielectric material, asurfactant, a filler material, and a coupling agent, the filler materialhaving at least a partial coating of the coupling agent thereon.

[0017] According to yet another aspect of the invention, there isprovided a hole fill composition comprising a fluoropolymer dielectricmaterial, a silica filler material, and a coupling agent, the fillermaterial having at least a partial coating of the coupling agentthereon.

[0018] According to still yet another aspect of the invention, there isprovided a hole fill composition comprising a fluoropolymer dielectricmaterial, a surfactant, a silica filler material, and a coupling agent,the filler material having at least a partial coating of the couplingagent thereon.

[0019] According to another aspect of the invention, there is provided ahole fill composition comprising a fluoropolymer dielectric material, afiller material, and a fluorosilane coupling agent, the filler materialhaving at least a partial coating of the coupling agent thereon.

[0020] According to yet another aspect of the invention, there isprovided a hole fill composition comprising a fluoropolymer dielectricmaterial, a surfactant, a filler material, and a fluorosilane couplingagent, the filler material having at least a partial coating of thecoupling agent thereon.

[0021] According to still yet another aspect of the invention, there isprovided a method of making a hole fill composition comprising the stepsof providing a quantity of a filler material, adding to the quantity ofthe filler material a quantity of coupling agent to at least partiallycoat the filler material, adding to the quantity of filler material atleast partially coated with the coupling agent a quantity of afluoropolymer dielectric material, and blending the filler materialcoated with the coupling agent and the fluoropolymer material.

[0022] According to another aspect of the invention, there is provided amethod of making a hole fill composition comprising the steps ofproviding a quantity of a filler material, dissolving a quantity ofcoupling agent in a first solvent to form a solution, mixing the fillermaterial into the solution to at least partially coat the fillermaterial, drying the filler material at least partially coated with thecoupling agent, adding the filler material at least partially coatedwith the coupling agent to a second solvent, adjusting the pH of thesecond solvent, dispersing a quantity of a fluoropolymer dielectricmaterial into the second solvent, adding a quantity of a surfactant tothe second solvent, and blending the filler material at least partiallycoated with the coupling agent and the fluoropolymer material.

[0023] According to yet another aspect of the invention, there isprovided a substrate comprising a metal layer including at least onethrough hole therein defined by at least one side wall within the metallayer, and a mixture of a fluoropolymer dielectric material and fillermaterial at least partially coated with a coupling agent positioned onthe side wall of the through hole, the mixture substantially filling thethrough hole in the metal layer.

[0024] According to still yet another aspect of the invention, there isprovided a substrate comprising a metal layer including at least onethrough hole therein defined by at least one side wall within the metallayer, and a mixture of a fluoropolymer dielectric material and a silicafiller material at least partially coated with a coupling agentpositioned on the side wall of the through hole, the mixturesubstantially filling the through hole in the metal layer.

[0025] According to another aspect of the invention, there is provided asubstrate comprising a metal layer including at least one through holetherein defined by at least one side wall within the metal layer, and amixture of a fluoropolymer dielectric material and a filler material atleast partially coated with a fluorosilane coupling agent positioned onthe side wall of the through hole, the mixture substantially filling thethrough hole in the metal layer.

[0026] According to yet another aspect of the invention, there isprovided a method of making a substrate comprising the steps ofproviding a metal layer including at least one through hole thereindefined by at least one side wall within the metal layer, positioning amixture of a fluoropolymer dielectric material and a filler material atleast partially coated with a coupling agent on the side wall of thethrough hole, and heating the metal layer, the fluoropolymer dielectricmaterial and the filler material at least partially coated with thecoupling agent to adhere the dielectric material and the filler materialto the side wall the dielectric material and the filler materialsubstantially filling the through hole.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027]FIG. 1 is a much-enlarged sectional view in elevation of asubstrate in accordance with the prior art.

[0028]FIG. 2 is a much-enlarged sectional view in elevation of oneembodiment of the substrate of the present invention, illustrating thesubstrate having a metal layer including at least one through holetherein, and a mixture of a fluoropolymer dielectric material and afiller material at least partially coated with a coupling agentsubstantially filling the through hole.

BEST MODE FOR CARRYING OUT THE INVENTION

[0029] In accordance with the teachings of this invention, there isprovided a new composition for use as a hole fill in the manufacture ofa substrate usable as part of a multilayer printed circuit board or chipcarrier. In one embodiment, this hole fill composition comprises afluoropolymer dielectric material, a filler material, and a couplingagent at least partially coating the filler material. A fluoropolymer isdefined as a carbon based organic polymer with fluorine atoms replacingat least some of the hydrogen atoms, covalently bound to the carbonatoms that form the basic chemical structure. It has been discoveredthat when the hole fill composition is utilized to fill through holes ina metal layer during the manufacture of a substrate, it results in aplanar substrate surface.

[0030] Referring to FIG. 1, a known substrate is shown. A non-planarsubstrate surface 2 can result when a fluoropolymer or similardielectric layer used in the manufacture of a multilayer printed circuitboard or chip carrier is laminated to a metal layer 6 having throughholes 8 (only one shown in FIG. 1). A non-planar substrate surface usedin the manufacture of a multilayer printed circuit board or chip carriercan result in a non-planar multilayer printed circuit board or chipcarrier outer surface of which the substrate is a part. A non-planarboard or chip carrier outer surface can adversely affect assembly ofcomponents, such as semiconductor chips, to the multilayer printedcircuit board or chip carrier surface and can result in increasedassembly defect levels and additional manufacturing costs.

[0031] A blistering defect between laminated dielectric layer 4 andmetal layer 6 of the substrate can occur during processing of themultilayer printed circuit board or chip carrier due to voids 9 beingpresent, after lamination, in the through hole locations. These voidscan occur because the properties of the dielectric material may notallow substantial uniform filling of the through holes in the metallayer during lamination.

[0032] The current hole fill composition substantially fills the throughholes in the metal layer of the substrate, provides a substantiallyplanar substrate surface and minimizes voids and blisters in the throughhole area, thereby reducing defect levels during manufacture or assemblyof components to the multilayer printed circuit board or chip carrier ofwhich the substrate is a part.

[0033] The fluoropolymer dielectric material of this invention isselected from the group consisting of polytetrafluoroethylene and itspolymers, copolymers of tetrafluorothylene, hexafluoropropylene,copolymers of tetrafluoroethylene, perfluoro-2-2-dimethyl-1,3 dioxide,polytrifluorochloroethylene, copolymers of trifluoromonochloroethylene,polymers of perfluoroalkyl vinyl ether, perfluorinatedethylene-propylene copolymers, copolymer of tetrafluoroethylene andperfluoroalkoxy, copolymer of tetrafluoro-ethylene and ethylene,copolymer of chlorotrifluoroethylene and ethylene, polymers ofchlorotrifluorethylene, polymers of chlorotrifluoroethylene, andcopolymer of tetrafluoroethylene and at least 65 mole % ofperfluoro-2,2-dimethyl-1,3-di-oxide.

[0034] The fluoropolymer dielectric material comprises about 40 percentby weight to about 90 percent by weight of the composition. Someexamples of commercially available fluoropolymer dielectric materialsthat are operable in this invention are TEFLON PTFE, TEFLON FEP, TEFLONPFA, TEFZEL, HFB-430 and TEFLON AF (all trademarks of E. I. Dupont deNemours and Co., Wilmington, Del.), HALAR (a trademark of Ausimont USA,Inc, Thorofare, N.J.), and Neoflon (a trade mark of CTFE produced byDarkin, Orangeburg, N.Y.).

[0035] The filler material that can be employed pursuant to the presentinvention comprises silica. The filler material comprises about percentby weight to about 60 percent by weight of the composition. The silica,having the chemical formula Sio₂, can be selected from the groupconsisting of crystalline silica, fumed silica, synthetic silica,precipitated silica and amorphous silica. Crystalline silica andamorphous silica are obtained/mined (ground and purified) from naturalsources. Purification removes other elements and ionic impurities. Thepurification step involves both thermal and chemical processes.Synthetic silica and precipitated silica can be obtained from sol(colloidal)/gel chemical processing of silanes, which involves thepolymerization of silanes into small insoluble silica particles. Such areaction permits the preparation of highly pure silica (without naturalmineral impurities) having controlled size and shape. Fumed silica is asynthetic silica prepared from the reaction of SiCl₄, hydrogen, andoxygen in the gas phase to form SiO₂. The silica particles can havesubstantially spherical or spheroidal shapes and have sizes of fromabout 0.1 microns to about 40 microns. The addition of silica particlesof this shape and size facilitates the composition such that it willreadily flow into and conform to the through hole shape of the metallayer and provides low thermal expansion properties, a very importantaspect of this invention.

[0036] A portion of each of the filler particles can include a layer ofa coupling agent positioned thereon to improve adhesion and moistureresistance. Coupling agents such as fluorosilanes including alkoxy orhalo groups can be used in this invention. Fluorosilane and alkoxy andhalo fluorosilanes, take the form of (R′)—Si—(R″, R′″, R″″). Silanes areorganic based silicon containing molecules. Typically the Si group isbound to an organic functional group (R′) such as alkane, alkene, phenylor aromatic groups or combinations thereof and may have fluoro, bromo,or chloro (halo) groups replacing the hydrogen atoms. The R′ group mayalso have a chemically active pendant group, such as an epoxy, amino,chloro, bromo, enabling it to react with other organic molecules. Theother three groups (R″, R′″, R″″) attached to the Si are typicallychloro, bromo, methoxy, or ethoxy and can react with each other in adisplacement reaction to form a monolayer on a silica or metal surfaceor together to form a network polymer. For example, coupling agents,such as 1H, 1H, 2H, 2H perflurooctyltriethoxysilane #12303-4 and 1H, 1H,2H, 2H perfluroalkyltriethoxysilane #12347-1, both available from PCRIncorporated, Gainesville, Fla., can be used in this invention. Anamount of coupling agent which is from about 1% by weight to about 10%by weight of the composition has been found satisfactory. The thicknessof the coupling agent on the filler particles can be as little as abouta few monolayers.

[0037] Surfactants can be used to facilitate mixing of the fillermaterial with the fluoropolymer dielectric in solution. Suitablesurfactants include those of the non-ionic type, available under theproduct name Triton X-100 from Rohm and Haas Co., Philadelphia, Pa.Other surface active agents that can be used in this invention includepolyoxyethylene/polyoxypropylene block copolymers commercially availableunder the trade name Pluronics, such as Pluronic L-62, Pluronic 31R1,and Pluronic L-92 from BASF Inc., Parsippany, N.J.

[0038] The compositions of the present invention may have a pH of fromabout 8 to about 11.

[0039] In accordance with another embodiment of this invention, a methodfor making the hole fill composition defined above is hereby provided.The method comprises the steps of providing a quantity of fillermaterial as defined hereinabove, adding to the quantity of fillermaterial a quantity of the above-defined coupling agent to at leastpartially coat the filler material, adding to the quantity of fillermaterial at least partially coated with the coupling agent a quantity ofthe fluoropolymer dielectric material of the type defined above and thenblending the filler material coated with the coupling agent and thefluoropolmer dielectric material. The filler material at least partiallycoated with the coupling agent can be prepared by dissolving thecoupling agent in a suitable solvent, such as isopropyl alcohol, andmixing the filler material into the coupling agent/solvent solution toform a slurry. The slurry can then be poured into an open vessel, airdried for about 12 hours, broken up into smaller particles, and furtherdried in an air oven at about 125° C. for about another 2 hours. Thestep of blending the filler material at least partially coated withcoupling agent and the fluoropolymer dielectric material can includeslowly adding the dried filler material into a solvent, such asdeionized water, with vigorous agitation to form a slurry, adjusting thepH of the deionized water/filler material slurry to a pH of from about 8to a pH of about 11 using ammonium hydroxide or another suitable base,and dispensing the fluoropolymer dielectric material into the pHadjusted deionized water/filler material slurry. A quantity ofsurfactant, such as defined above, can be added with stirring until thesurfactant is dissolved.

[0040] In accordance with yet another embodiment of this invention,referring to FIG. 2, there is also provided a substrate 10 whichincludes a metal layer 16 including at least one through hole 18 thereindefined by at least one side wall 20 within the metal layer, and amixture 22 of the above-identified fluoropolymer dielectric material andthe above-defined filler material at least partially coated with acoupling agent, as described above, positioned on the side wall of thethrough hole, the mixture substantially filling the through hole in themetal layer. The metal layer 16 of substrate 10 is selected from thegroup consisting of nickel, copper, cobalt, molybdenum, iron and alloysthereof. For example, one alloy that can be used as the metal layer ofthis invention is Invar clad with a layer of copper. Invar can bedefined as an alloy having a composition of about 34% to about 0.38%nickel and about 62% to about 66% iron. A suitable alloy of this type isavailable from Texas Instruments Incorporated (Attleboro, Mass.).

[0041] In accordance with still yet another embodiment of thisinvention, a method for making the substrate defined above is herebyprovided. The method comprises the steps of providing a metal layerincluding at least one through hole therein defined by at least one sidewall within the metal layer, as defined hereinabove, positioning amixture of the above-defined fluoropolymer dielectric material and afiller material of the type defined above at least partially coated withthe above-defined coupling agent on the side wall of the through hole,and heating the metal layer, fluoropolymer dielectric material, andfiller material to a temperature of up to about 80 degrees centigradeabove the fluoropolymer melting temperature to adhere the dielectricmaterial and filler material to the side wall of the through hole, thedielectric material and the filler material substantially filling thethrough hole. This will form a substantially planar substrate surface.During the heating step, the surfactant employed in the production ofthe fill composition is substantially burned off. For example, when thefluoropolymer dielectric material is TEFLON PTFE, its meltingtemperature is about 327 degrees centigrade, so the heating temperaturewould be in the range of about 327 degrees centigrade to about 407degrees centigrade.

[0042] The through hole in the metal layer can be provided by the stepof drilling, punching or etching.

[0043] The filler material and the fluoropolymer dielectric material areadhered to the side wall of the through hole by fusion during theheating step. Fusion is the process by which the fluoropolymerdielectric material and the filler material are heated above thefluoropolymer melt temperature so that the fluoropolymer and filleradhere to the side wall by a combination of mechanical and chemicalinterlocking once the temperature is reduced below the melt temperature.

[0044] The invention provides a novel hole fill composition and methodof making the composition which can substantially fill through holes inthe metal layer of a substrate, provides a substantially planarsubstrate surface, and minimizes voids and blisters in the through holearea, thereby reducing defect levels during manufacture or assembly ofcomponents to the multilayer printed circuit board or chip carrier ofwhich the substrate is a part.

[0045] While there have been shown and described what are the presentconsidered preferred embodiments of the invention, it will be obvious tothose skilled in the art that various changes and modifications may bemade therein without departing from the scope of the invention asdefined by the appended claims.

We claim:
 1. A hole fill composition comprising: a fluoropolymerdielectric material; a filler material; and a coupling agent, saidfiller material having at least a partial coating of said coupling agentthereon.
 2. The composition of claim 1 wherein said fluoropolymerdielectric material is selected from the group consisting of polymers oftetrafluoroethylene and its copolymers including tetrafluoroethylene andperfluoroalkoxy, tetrafluoroethylene and ethylene, andtetrafluoroethylene and at least 65 mole % ofperfluoro-2,2-dimethyl-1,3-di-oxide; hexafluoropropylene;perfluoro-2-2-dimethyl-1,3 dioxide; polymers and copolymers oftrifluorochloroethylene including trifluorochloroethylene and ethylene;polymers of perfluoroalkyl vinyl ether; and perfluorinatedethylene-propylene copolymers.
 3. The composition of claim 1 whereinsaid fluoropolymer dielectric material comprises about 40 percent byweight to about 90 percent by weight of said composition.
 4. Thecomposition of claim 1 wherein said filler material comprises about 9percent by weight to about 60 percent by weight of said composition. 5.The composition of claim 1 wherein said coupling agent comprises about 1percent by weight to about 10 percent by weight of said composition. 6.The invention of claim 1 wherein said composition has a pH of about 8 toabout
 11. 7. A hole fill composition comprising: a fluoropolymerdielectric material; a surfactant; a filler material; and a couplingagent, said filler material having at least a partial coating of saidcoupling agent thereon.
 8. The composition of claim 7 wherein saidsurfactant comprises a non-ionic surface active agent.
 9. A hole fillcomposition comprising: a fluoropolymer dielectric material; a silicafiller material; and a coupling agent, said filler material having atleast a partial coating of said coupling agent thereon.
 10. Thecomposition of claim 9 wherein said fluoropolymer dielectric material isselected from the group consisting of polymers of tetrafluoroethyleneand its copolymers, including tetrafluoroethylene and perfluoroalkoxy,tetrafluoroethylene and ethylene, and tetrafluoroethylene and at least65 mole % of perfluoro-2,2-dimethyl-1,3-di-oxide; hexafluoropropylene;perfluoro-2-2-dimethyl-1,3 dioxide; polymers and copolymers oftrifluorochloroethylene including trifluorochloroethylene and ethylene;polymers of perfluoroalkyl vinyl ether; and perfluorinatedethylene-propylene copolymers.
 11. The composition of claim 9 whereinsaid fluoropolymer dielectric material comprises about 40 percent byweight to about 90 percent by weight of said composition.
 12. Thecomposition of claim 9 wherein said silica of said silica filler isselected from the group consisting of crystalline silica, fumed silica,synthetic silica, precipitated silica, and amorphous silica.
 13. Thecomposition of claim 9 wherein said silica filler material comprisesabout 9 percent by weight to about 60 percent by weight of saidcomposition.
 14. The composition of claim 9 wherein said silica of saidsilica filler material is comprised of particles, each particle having asize of from about 0.1 micron to about 40 microns.
 15. The compositionof claim 14 wherein said particles of silica are substantially sphericalor spheroidal.
 16. The composition of claim 9 wherein said couplingagent comprises about 1 percent by weight to about 10 percent by weightof said composition.
 17. The invention of claim 9 wherein saidcomposition has a pH of about 8 to about
 11. 18. A hole fill compositioncomprising: a fluoropolymer dielectric material; a surfactant; a silicafiller material; and a coupling agent, said filler material having atleast a partial coating of said coupling agent thereon.
 19. Thecomposition of claim 18 wherein said surfactant comprises a non-ionicsurface active agent.
 20. A hole fill composition comprising: afluoropolymer dielectric material; a filler material; and a fluorosilanecoupling agent, said filler material having at least a partial coatingof said coupling agent thereon.
 21. The composition of claim 20 whereinsaid fluoropolymer dielectric material is selected from the groupconsisting of polymers of tetrafluoroethylene and its copolymers,including tetrafluoroethylene and perfluoroalkoxy, tetrafluoroethyleneand ethylene, and tetrafluoroethylene and at least 65 mole % ofperfluoro-2,2-dimethyl-1,3-di-oxide; hexafluoropropylene;perfluoro-2-2-dimethyl-1,3 dioxide; polymers and copolymers oftrifluorochloroethylene including trifluorochloroethylene and ethylene;polymers of perfluoroalkyl vinyl ether; and perfluorinatedethylene-propylene copolymers.
 22. The composition of claim 20 whereinsaid fluoropolymer dielectric material comprises about 40 percent byweight to about 90 percent by weight of said composition.
 23. Thecomposition of claim 20 wherein said filler material comprises about 9percent by weight to about 60 percent by weight of said composition. 24.The composition of claim 20 wherein said fluorosilane coupling agentincludes alkoxy or halo groups attached to an Si group.
 25. Thecomposition of claim 20 wherein said fluorosilane coupling agentcomprises about 1 percent by weight to about 10 percent by weight ofsaid composition.
 26. The invention of claim 20 wherein said compositionhas a pH of about 8 to about
 11. 27. A hole fill composition comprising:a fluoropolymer dielectric material; a surfactant; a filler material;and a fluorosilane coupling agent, said filler material having at leasta partial coating of said coupling agent thereon.
 28. The composition ofclaim 27 wherein said surfactant comprises a non-ionic surface activeagent.